兼容 IOS

ios/Runner/RecordingPlugin.swift

@@ -336,7 +336,9 @@ private final class RecordingCameraController: NSObject, AVCaptureFileOutputReco
       }
 
       do {
-        let nextZoom = self.clampedZoomRatio(ratio, for: device)
+        // 入参是显示倍率(1.0x = 主摄)，按 S 基准换算回设备 zoomFactor。
+        let baseline = self.mainBaselineFactor(for: device)
+        let nextZoom = self.clampedZoomRatio(ratio * baseline, for: device)
         try device.lockForConfiguration()
         device.videoZoomFactor = nextZoom
         device.unlockForConfiguration()
@@ -427,11 +429,7 @@ private final class RecordingCameraController: NSObject, AVCaptureFileOutputReco
       return
     }
 
-    guard
-      let videoDevice = AVCaptureDevice.default(
-        .builtInWideAngleCamera, for: .video, position: .back)
-        ?? AVCaptureDevice.default(for: .video)
-    else {
+    guard let videoDevice = Self.preferredVideoDevice() else {
       throw NSError(
         domain: "RecordingCamera", code: 1,
         userInfo: [NSLocalizedDescriptionKey: "No camera device available"])
@@ -461,10 +459,39 @@ private final class RecordingCameraController: NSObject, AVCaptureFileOutputReco
     session.commitConfiguration()
 
     configured = true
+    // 默认以主摄(显示 1.0x)开场：虚拟多摄设备里主摄对应的 zoomFactor 是 S。
+    currentZoomRatio = mainBaselineFactor(for: videoDevice)
     try applyCurrentZoom()
     try configureAudioInput(enabled: withAudio)
   }
 
+  /// 优先选用包含超广角的虚拟多摄设备，使 minAvailableVideoZoomFactor 能低于主摄(从而支持 0.6x)。
+  private static func preferredVideoDevice() -> AVCaptureDevice? {
+    let preferredTypes: [AVCaptureDevice.DeviceType] = [
+      .builtInTripleCamera,
+      .builtInDualWideCamera,
+      .builtInWideAngleCamera,
+    ]
+    for type in preferredTypes {
+      if let device = AVCaptureDevice.default(type, for: .video, position: .back) {
+        return device
+      }
+    }
+    return AVCaptureDevice.default(for: .video)
+  }
+
+  /// 虚拟多摄设备中「主摄(显示 1.0x)」对应的设备 zoomFactor 基准 S。
+  /// 取 ultra-wide → wide 的切换点；非虚拟设备无切换点时返回 1.0(向后兼容)。
+  private func mainBaselineFactor(for device: AVCaptureDevice) -> CGFloat {
+    if let first = device.virtualDeviceSwitchOverVideoZoomFactors.first {
+      let value = CGFloat(truncating: first)
+      if value > 0 {
+        return value
+      }
+    }
+    return 1.0
+  }
+
   private func currentZoomCapabilitiesMap() -> [String: Any] {
     guard let device = videoInput?.device else {
       return [
@@ -474,14 +501,16 @@ private final class RecordingCameraController: NSObject, AVCaptureFileOutputReco
       ]
     }
 
+    // 设备 zoomFactor 以 S 为基准换算成 App 使用的「显示倍率」(1.0x = 主摄)。
+    let baseline = mainBaselineFactor(for: device)
     let minZoom = device.minAvailableVideoZoomFactor
     let maxZoom = device.maxAvailableVideoZoomFactor
     let zoom = clampedZoomRatio(device.videoZoomFactor, for: device)
     currentZoomRatio = zoom
     return [
-      "zoomRatio": Double(zoom),
-      "minZoomRatio": Double(minZoom),
-      "maxZoomRatio": Double(maxZoom),
+      "zoomRatio": Double(zoom / baseline),
+      "minZoomRatio": Double(minZoom / baseline),
+      "maxZoomRatio": Double(maxZoom / baseline),
     ]
   }